In a 5g I would recommend only some shrimp. especially since it is a tall tank. amano shrimp are usually good choices with bettas. Much more attractive than ghost shrimp, but cherries are a bit small and can be eaten by th betta. A snail could be another possibility if you fancied it.

ive had snails before-they reproduce like crazy, not for me
but the amano shrimp idea sounds alright. what do they eat? how big do they get? do they need special substrait? do you need them in flocks so they dont get lonley? and i guess they need 98 degree temp just like bettas?

The eat algae, they get about 2 inches. I don't think they need anything special for substrate, I dunno if they get lonely or not-I have cherries and they could take or leave each other, and as for temp I'm hoping thats a typo and you keep it around 78 degrees, not 98 :)

as for temp I'm hoping thats a typo and you keep it around 78 degrees, not 98 :)

ooooo. whoops yup typo. i dont think they would appreciate getting boiled alive. 78 i what i meant
my tank doesnt really get that much algae so ill just pick up sinking agae discs when i get the shrimp. Ill start with 2 shrimp and see from there

i didnt know if they would eat exess fish food like the brine shrimp i give Rambo (betta) or if they frown apon cannibleisnm

if you like snails, but just don't want them to reproduce then you could get a mystery snail. it can't reproduce on it's own anyway and also, if you have a pair and they lay eggs, they lay a clutch above the water line which is easily removed. if you're happy with the shrimp though then go for them. I'd put 3 in the tank if it were mine.